With so much discussion about health problems related to being overweight or obese, the topic of undereating may not appear to a huge concern, but believe me, it is. Often, when individuals are working on weight loss, fitness gain or performance optimization, the issue of undereating comes up just as frequently as overeating does. We all know why it’s so easy to eat too much: portion sizes have expanded dramatically, bulk buying habits encourage us to keep more food around at all times, we’ve been encouraged to snack in between meals with little regard for hunger cues, and so many of our modern foods are less satiating than fresh, wholesome food we ate just a generation or two ago (low in fiber and protein, high in refined carbohydrates).
It’s not so easy to understand why so many people are chronically undereating for their health, but a major contributor is the emphasis on calorie math that leads so many people into risky dieting patterns. Don’t get me wrong, managing calories appropriately is critical for weight loss and body composition management. However, if we’re not careful, a calorie math-focused mindset can be a risk factor for a number of negative adaptations.
Logically, chopping a couple hundred calories out of your daily intake can seem like a no-brainer way to encourage your body to burn extra energy from fat stores. And it will probably work for most people – at least temporarily. As many internet calorie calculators would have you believe, if you want faster results you can choose a larger energy deficit and get a faster linear path to weight loss. So if eliminating 300 Calories from your normal day is good, dropping 500 or 1000 Calories is even better, right?
It’s just not that easy! Our physiology is smart. It likes balance and homeostasis. We’re wired for survival, not for six-pack abs. If you’ve found yourself in a place where you’ve followed “diets” below your true caloric needs for any length of time, you’ve probably begun to experience at least some of the negative consequences of not eating enough.
It takes a trained eye to spot the main indications of not eating enough. But once you learn these main signals, you’ll be more likely to enjoy continued progress towards your goals through more ideal eating patterns. Note: the downfalls of “not eating enough” discussed below are in the context of persistent or prolonged undereating (longer than a few weeks), not necessarily indicative of missing a single meal or eating too little for a couple of days.
Your diet changes who you are.
Irritable, anxious, mentally exhausted, foggy-brained, unable to focus, or mildly obsessed with or fixated on food? Sounds like what happens when you go on a diet, right? Most of us have experienced episodes of “hanger” or mustered through periods of difficult concentration on our mission to lose a few pounds of pudge.
It is not wise to take these mood or cognitive changes lightly though. They are serious signs that your metabolism is beginning to make negative adaptations to the caloric deficit you’re experiencing. Our brains consume about 20% of our total energy expenditure, which is why when you go on a lower-calorie diet by restricting total intake by 20 to 50%, you become a fundamentally different person. Whether it’s the frank energy shortage or insufficient intake of nutrients your brain depends on to maintain healthy neurotransmitter levels, undereating leads to significant brain changes.
If your brain is chronically deprived of energy to operate at full capacity, you’re eventually going to experience cognitive deficits including memory changes, impaired alertness, judgement or concentration. If the energy deficit is extreme enough – like the restriction experienced by subjects of the Minnesota Starvation Experiment of the 1940’s – the mental and cognitive changes can border on psychosis and perhaps even be permanent. Those subjects were fed an average of 1600 calories per day during the six month “starvation” phase of the experiment.
This was a 50% calorie reduction from their baseline, which sounds extreme, but compared to many persons, this is not an unrealistic difference between “normal” eating and their “dieting” intakes. The effects of “starvation” on these subjects were profound, and included changes in sense of humor, increased self-criticism, and altogether negative changes to social affect. Even without cutting calorie intake in half, conscious calorie monitoring or restriction increases cortisol output and perceived stress. In other words, consciously not eating “enough” automatically makes you less resilient against the stresses of daily life.
This shows us how important it is to complement any “dieting” efforts with a healthy amount of monitoring of our mental and social well-being through strong social support systems and consistent self-reflection or gratitude. Calories are not more important than character. If you sense your mood, cognition or personality changing, it may be one of the first indicators that your “diet” is leading to negative adaptations.
Your physical health suffers.
Often times, we ignore the first negative signs of not eating enough (brain changes) because we’re motivated by aesthetically-focused outcomes. So, we press on and suffer through the next set of negative adaptations that can arise from chronic under-feeding; physical breakdown. Sometimes it can be difficult to tell if these changes are completely negative or just part of the process of improving fitness. Because experiencing soreness, lowering resting pulse and blood pressure, and some fatigue are to be expected as we go through a training or weight loss program. However, one must continually evaluate their physical resilience to make sure their calorie intake is sufficient to maintain their health as their physique changes.
To lose weight the right way, you can’t just monitor your scale weight. You must measure other indicators of physical change such as body fat changes, lean mass levels, physical performance and physical health. Are your skin, hair, and nails looking healthier and are you feeling younger as you trim down or are you noticing visual and sensory signs of premature aging?
For example, if you’re losing more muscle than fat, you’re not eating enough. If you’re not gaining or maintaining your physical strength or abilities week to week, you’re probably not eating enough. If you’re noticing extended soreness after workouts, prolonged healing time, or your hair is falling out more easily, you’re definitely not feeding your body enough to positively adapt to your program.
Evidence suggests that eating enough calories to support progressively harder physical training (as opposed to cutting calories to induce weight loss) is the better way to promote physical health and physique changes (loss of body fat and gain of lean tissue). At least one study showed significantly poorer exercise performance capacity when subjects restricted their calories by an average of 12% from their baseline. The subjects experienced dramatic decreases in VO2, muscle size and muscle strength over the course of twelve months.
It’s commonly assumed that maximizing fat loss is often accompanied by performance plateaus and/or mild decreases, but this study suggested energy deficits created through smart training rather than dietary restriction ultimately results in both fat loss and performance improvement. That’s the holy grail of health improvement, and it happens when we’re fed well enough to physically repair from the exercise stress we encounter. Unfortunately, many people try to chronically diet and exercise to double up on the calorie math advantage. What happens after more than a couple weeks of this?
Your hormonal ‘soup’ sours.
The longer your body experiences under-nourishment, the more severely it will adapt. The adaptations are aimed at survival, so any system that’s not absolutely necessary to survival gets down-regulated. As mentioned above, our stress hormones elevate mainly to support the energy needs of our vital organs (at the expense of all other tissues like muscle).
Chronic elevations in cortisol can cause the hormones that control our metabolic rate to decrease significantly, sometimes in as little as a few weeks of being on an energy restricted diet. This decrease results in a decrease in our body temperature, brain activity, heart rate, digestive processes and just about every other system in our body. Reproductive hormones often plummet (mainly testosterone in men and progesterone in women) so much that libido, affect and reproductive cycles become severely or even permanently deranged.
It’s quite unfortunate, but the repeated cycles of dieting and weight re-gain often lead to significant alterations in hormonal balance, which are often combatted by even more extreme dieting patterns. It’s a vicious cycle.
What to do
You may not like this advice, but in order to optimize your fat loss and fitness, you probably need to abandon hopes of quick success and focus on the (slower) road to prolonged health. Ditch the use of internet-based calorie calculators that only account for your age, gender, height and weight. These calculators do not account for your dieting or exercise history, so they can only apply an overly-simplified calorie math equation that cannot predictably help you optimize your physiology. Consult with a Registered Dietitian Nutritionist who can provide an individual assessment of you metabolism and physiology needs. Happy Healthy!!
Adapted from: Paul Kriegler, RD
Nutrition Tip of the Day
Find Time To Sleep! No amount of multivitamins, super foods or juices can help you if you are neglecting your REM cycle. Sleeping seven plus hours per night is required in order for the body to detoxify, repair and rebuild for the next day. When you are tired you will oftentimes opt for food that is high in sugar and caffeine to give you that temporary energy boost. Failing to ignore your body’s silent cries for sleep can result in potential health issues, as well as weight gain.